[PATCH] Allow value repeat operator on references

[PATCH] Allow value repeat operator on references

[Hannes Domani]

Currently it's not possible to use the value repeat operator on references:
```
print ((int &) v_int_array_init[0])@2
Only values in memory can be extended with '@'.
```

This seems like an unnecessary restriction, since it also prevents
its use on iterators (which was the original reported problem):
```
(gdb) p *it@2
Only values in memory can be extended with '@'.
```

So this converts any references to the referenced value in value_repeat,
making this possible:
```
print ((int &) v_int_array_init[0])@2
$1 = {10, 20}
(gdb) p *it@2
$2 = {1, 2}
```
---
 gdb/testsuite/gdb.base/exprs.exp | 1 +
 gdb/valops.c                     | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/gdb/testsuite/gdb.base/exprs.exp b/gdb/testsuite/gdb.base/exprs.exp
index 239cdce8dc2..0f8c53bc716 100644
--- a/gdb/testsuite/gdb.base/exprs.exp
+++ b/gdb/testsuite/gdb.base/exprs.exp
@@ -259,6 +259,7 @@ gdb_test {print *v_int_array_init@2} { = \{10, 20\}}
 gdb_test {print v_int_array_init[0]@1} { = \{10\}}
 gdb_test {print v_int_array_init[0]@2} { = \{10, 20\}}
 gdb_test {print v_int_array_init[1]@1} { = \{20\}}
+gdb_test {print ((int &) v_int_array_init[0])@2} { = \{10, 20\}}
 
 # gdb's {} extension
 gdb_test_no_output "set variable v_short_array\[0\] = 42"
diff --git a/gdb/valops.c b/gdb/valops.c
index e2694f0c32b..399d0f109e1 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1349,6 +1349,8 @@ value_repeat (struct value *arg1, int count)
 {
   struct value *val;
 
+  arg1 = coerce_ref (arg1);
+
   if (arg1->lval () != lval_memory)
     error (_("Only values in memory can be extended with '@'."));
   if (count < 1)
-- 
2.35.1

Re: [PATCH] Allow value repeat operator on references

[Kevin Buettner]

On Fri,  9 Feb 2024 14:04:51 +0100
Hannes Domani <ssbssa@yahoo.de> wrote:

> Currently it's not possible to use the value repeat operator on references:
> ```
> print ((int &) v_int_array_init[0])@2
> Only values in memory can be extended with '@'.
> ```
> 
> This seems like an unnecessary restriction, since it also prevents
> its use on iterators (which was the original reported problem):
> ```
> (gdb) p *it@2
> Only values in memory can be extended with '@'.
> ```
> 
> So this converts any references to the referenced value in value_repeat,
> making this possible:
> ```
> print ((int &) v_int_array_init[0])@2
> $1 = {10, 20}
> (gdb) p *it@2
> $2 = {1, 2}
> ```
> ---
>  gdb/testsuite/gdb.base/exprs.exp | 1 +
>  gdb/valops.c                     | 2 ++
>  2 files changed, 3 insertions(+)

LGTM.

Approved-by: Kevin Buettner <kevinb@redhat.com>

Re: [PATCH] Allow value repeat operator on references

[Hannes Domani]

 Am Freitag, 9. Februar 2024 um 20:14:41 MEZ hat Kevin Buettner <kevinb@redhat.com> Folgendes geschrieben:

> On Fri,  9 Feb 2024 14:04:51 +0100
>
> Hannes Domani <ssbssa@yahoo.de> wrote:
>
> > Currently it's not possible to use the value repeat operator on references:
> > ```
> > print ((int &) v_int_array_init[0])@2
> > Only values in memory can be extended with '@'.
> > ```
> >
> > This seems like an unnecessary restriction, since it also prevents
> > its use on iterators (which was the original reported problem):
> > ```
> > (gdb) p *it@2
> > Only values in memory can be extended with '@'.
> > ```
> >
> > So this converts any references to the referenced value in value_repeat,
> > making this possible:
> > ```
> > print ((int &) v_int_array_init[0])@2
> > $1 = {10, 20}
> > (gdb) p *it@2
> > $2 = {1, 2}
> > ```
> > ---
> >  gdb/testsuite/gdb.base/exprs.exp | 1 +
> >  gdb/valops.c                    | 2 ++
> >  2 files changed, 3 insertions(+)
>
>
> LGTM.
>
> Approved-by: Kevin Buettner <kevinb@redhat.com>

Pushed, thanks.


Hannes